Carbohydrate metabolism: alpha-glucosidase inhibitors: practice question

A Biochemistry question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Biochemistry · Carbohydrate metabolism: alpha-glucosidase inhibitors

Sample item

A man with type 2 diabetes is started on a tablet that lowers the rise in blood glucose after starchy meals but causes flatulence and bloating. Which enzymes does the drug inhibit?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Intestinal brush-border alpha-glucosidases

Acarbose inhibits intestinal alpha-glucosidases that release absorbable monosaccharides from oligosaccharides, delaying carbohydrate absorption and blunting the postprandial peak. Undigested carbohydrate reaches the colon, where bacterial fermentation produces gas.

Option by option

  • A. Dipeptidyl peptidase-4

    Dipeptidyl peptidase-4 degrades incretins and is the target of gliptins, which do not cause flatulence.

  • B. Pancreatic lipase

    Pancreatic lipase digests triglyceride and is inhibited by orlistat, not by drugs for starch digestion.

  • C. Hepatic glucose-6-phosphatase

    Hepatic glucose-6-phosphatase releases glucose in gluconeogenesis and glycogenolysis and is not a drug target here.

  • D. Intestinal brush-border alpha-glucosidases (correct)

    Correct. Blocking alpha-glucosidases delays glucose absorption and leaves carbohydrate for colonic fermentation.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Biochemistry question

What is the answer to this Biochemistry question?

The best answer is D, Intestinal brush-border alpha-glucosidases. Acarbose inhibits intestinal alpha-glucosidases that release absorbable monosaccharides from oligosaccharides, delaying carbohydrate absorption and blunting the postprandial peak.

Why is "Dipeptidyl peptidase-4" not the answer?

Dipeptidyl peptidase-4 degrades incretins and is the target of gliptins, which do not cause flatulence.

Why is "Pancreatic lipase" not the answer?

Pancreatic lipase digests triglyceride and is inhibited by orlistat, not by drugs for starch digestion.

Why is "Hepatic glucose-6-phosphatase" not the answer?

Hepatic glucose-6-phosphatase releases glucose in gluconeogenesis and glycogenolysis and is not a drug target here.

What concept does this question test?

It tests Carbohydrate metabolism: alpha-glucosidase inhibitors in Biochemistry. Undigested carbohydrate reaches the colon, where bacterial fermentation produces gas.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Carbohydrate metabolism: alpha-glucosidase inhibitors?

Build one table of enzyme deficiency, disease, inheritance and key finding, then revise it by spaced recall. Then use the flashcards and the other Biochemistry questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.